#ifndef _GPXE_NETDEVICE_H
#define _GPXE_NETDEVICE_H
/** @file
*
* Network device management
*
*/
#include <stdint.h>
#include <gpxe/tables.h>
struct pk_buff;
struct net_device;
struct net_protocol;
struct ll_protocol;
/** Maximum length of a link-layer address */
#define MAX_LL_ADDR_LEN 6
/** Maximum length of a link-layer header */
#define MAX_LL_HEADER_LEN 16
/** Maximum length of a network-layer address */
#define MAX_NET_ADDR_LEN 4
/* Network-layer address may be required to hold a link-layer address
* (if NETADDR_FL_RAW is set
*/
#if MAX_NET_ADDR_LEN < MAX_LL_ADDR_LEN
#undef MAX_NET_ADDR_LEN
#define MAX_NET_ADDR_LEN MAX_LL_ADDR_LEN
#endif
/** A generic network-layer header */
struct net_header {
/** Network-layer protocol */
struct net_protocol *net_protocol;
/** Flags
*
* This is the bitwise OR of zero or more PKT_FL_XXX
* values.
*/
int flags;
/** Network-layer destination address */
uint8_t dest_net_addr[MAX_NET_ADDR_LEN];
/** Network-layer source address */
uint8_t source_net_addr[MAX_NET_ADDR_LEN];
};
/** Packet is a broadcast packet */
#define PKT_FL_BROADCAST 0x01
/** Packet is a multicast packet */
#define PKT_FL_MULTICAST 0x02
/** Addresses are raw hardware addresses */
#define PKT_FL_RAW_ADDR 0x04
/** A generic link-layer header */
struct ll_header {
/** Link-layer protocol */
struct ll_protocol *ll_protocol;
/** Flags
*
* This is the bitwise OR of zero or more PKT_FL_XXX
* values.
*/
int flags;
/** Link-layer destination address */
uint8_t dest_ll_addr[MAX_LL_ADDR_LEN];
/** Link-layer source address */
uint8_t source_ll_addr[MAX_LL_ADDR_LEN];
/** Network-layer protocol
*
*
* This is an ETH_P_XXX constant, in network-byte order
*/
uint16_t net_proto;
};
/**
* A network-layer protocol
*
*/
struct net_protocol {
/** Protocol name */
const char *name;
/**
* Perform network-layer routing
*
* @v pkb Packet buffer
* @v nethdr Generic network-layer header
* @ret rc Return status code
*
* This method should fill in the network header with enough
* information to allow the link layer to route the packet.
*
* For example, in the case of IPv4, this method should fill
* in the IP addresses of the local adapter and the next hop
* destination (e.g. the gateway).
*/
int ( * route ) ( const struct pk_buff *pkb,
struct net_header *nethdr );
/**
* Handle received packets
*
* @v pkb Packet buffer
* @ret rc Return status code
*
* If this method returns success, it has taken ownership of
* the packet buffer.
*/
int ( * rx ) ( struct pk_buff *pkb );
/**
* Transcribe network-layer address
*
* @v net_addr Network-layer address
* @ret string Human-readable transcription of address
*
* This method should convert the network-layer address into a
* human-readable format (e.g. dotted quad notation for IPv4).
*
* The buffer used to hold the transcription is statically
* allocated.
*/
const char * ( *ntoa ) ( const void * net_addr );
/** Network-layer protocol
*
* This is an ETH_P_XXX constant, in network-byte order
*/
uint16_t net_proto;
/** Network-layer address length */
uint8_t net_addr_len;
};
/**
* A link-layer protocol
*
*/
struct ll_protocol {
/** Protocol name */
const char *name;
/**
* Perform link-layer routing
*
* @v netdev Network device
* @v nethdr Generic network-layer header
* @ret llhdr Generic link-layer header
* @ret rc Return status code
*
* This method should construct the generic link-layer header
* based on the generic network-layer header.
*
* If a link-layer header cannot be constructed (e.g. because
* of a missing ARP cache entry), then this method should
* return an error (after transmitting an ARP request, if
* applicable).
*/
int ( * route ) ( struct net_device *netdev,
const struct net_header *nethdr,
struct ll_header *llhdr );
/**
* Fill media-specific link-layer header
*
* @v llhdr Generic link-layer header
* @v pkb Packet buffer
*
* This method should fill in the link-layer header in the
* packet buffer based on information in the generic
* link-layer header.
*/
void ( * fill_llh ) ( const struct ll_header *llhdr,
struct pk_buff *pkb );
/**
* Parse media-specific link-layer header
*
* @v pkb Packet buffer
* @v llhdr Generic link-layer header
*
* This method should fill in the generic link-layer header
* based on information in the link-layer header in the packet
* buffer.
*/
void ( * parse_llh ) ( const struct pk_buff *pkb,
struct ll_header *llhdr );
/**
* Transcribe link-layer address
*
* @v ll_addr Link-layer address
* @ret string Human-readable transcription of address
*
* This method should convert the link-layer address into a
* human-readable format.
*
* The buffer used to hold the transcription is statically
* allocated.
*/
const char * ( *ntoa ) ( const void * ll_addr );
/** Link-layer protocol
*
* This is an ARPHRD_XXX constant, in network byte order.
*/
uint16_t ll_proto;
/** Link-layer address length */
uint8_t ll_addr_len;
/** Link-layer header length */
uint8_t ll_header_len;
};
/**
* A network-layer address assigned to a network device
*
*/
struct net_address {
/** Network-layer protocol */
struct net_protocol *net_protocol;
/** Network-layer address */
uint8_t net_addr[MAX_NET_ADDR_LEN];
};
/**
* A network device
*
* This structure represents a piece of networking hardware. It has
* properties such as a link-layer address and methods for
* transmitting and receiving raw packets.
*
* Note that this structure must represent a generic network device,
* not just an Ethernet device.
*/
struct net_device {
/** Transmit packet
*
* @v netdev Network device
* @v pkb Packet buffer
* @ret rc Return status code
*
* This method should cause the hardware to initiate
* transmission of the packet buffer.
*
* If the method returns success, ownership of the packet
* buffer is transferred to the @c net_device, which must
* eventually call free_pkb() to release the buffer.
*/
int ( * transmit ) ( struct net_device *netdev, struct pk_buff *pkb );
/** Poll for received packet
*
* @v netdev Network device
*
* This method should cause the hardware to check for received
* packets. Any received packets should be delivered via
* netdev_rx().
*/
void ( * poll ) ( struct net_device *netdev );
/** Link-layer protocol */
struct ll_protocol *ll_protocol;
/** Link-layer address
*
* For Ethernet, this is the MAC address.
*/
uint8_t ll_addr[MAX_LL_ADDR_LEN];
/** Driver private data */
void *priv;
};
extern struct net_device static_single_netdev;
/**
* Allocate network device
*
* @v priv_size Size of private data area (net_device::priv)
* @ret netdev Network device, or NULL
*
* Allocates space for a network device and its private data area.
*
* This macro allows for a very efficient implementation in the case
* of a single static network device; it neatly avoids dynamic
* allocation and can never return failure, meaning that the failure
* path will be optimised away. However, driver writers should not
* rely on this feature; the drivers should be written to allow for
* multiple instances of network devices.
*/
#define alloc_netdev( priv_size ) ( { \
static char priv_data[priv_size]; \
static_single_netdev.priv = priv_data; \
&static_single_netdev; } )
/**
* Register network device
*
* @v netdev Network device
* @ret rc Return status code
*
* Adds the network device to the list of network devices.
*/
static inline int
register_netdev ( struct net_device *netdev __attribute__ (( unused )) ) {
return 0;
}
/**
* Unregister network device
*
* @v netdev Network device
*
* Removes the network device from the list of network devices.
*/
static inline void
unregister_netdev ( struct net_device *netdev __attribute__ (( unused )) ) {
/* Nothing to do */
}
/**
* Free network device
*
* @v netdev Network device
*/
static inline void
free_netdev ( struct net_device *netdev __attribute__ (( unused )) ) {
/* Nothing to do */
}
/**
* Transmit raw packet via network device
*
* @v netdev Network device
* @v pkb Packet buffer
* @ret rc Return status code
*
* Transmits the packet via the specified network device. The
* link-layer header must already have been filled in. If this
* function returns success, it has taken ownership of the packet
* buffer.
*/
static inline int netdev_transmit ( struct net_device *netdev,
struct pk_buff *pkb ) {
return netdev->transmit ( netdev, pkb );
}
/**
* Register a link-layer protocol
*
* @v protocol Link-layer protocol
*/
#define LL_PROTOCOL( protocol ) \
struct ll_protocol protocol __table ( ll_protocols, 01 )
/**
* Register a network-layer protocol
*
* @v protocol Network-layer protocol
*/
#define NET_PROTOCOL( protocol ) \
struct net_protocol protocol __table ( net_protocols, 01 )
/**
* Register a network-layer address for the static single network device
*
* @v net_address Network-layer address
*/
#define STATIC_SINGLE_NETDEV_ADDRESS( address ) \
struct net_address address __table ( sgl_netdev_addresses, 01 )
extern void netdev_rx ( struct net_device *netdev, struct pk_buff *pkb );
extern struct net_protocol *find_net_protocol ( uint16_t net_proto );
extern struct net_device *
find_netdev_by_net_addr ( struct net_protocol *net_protocol, void *net_addr );
extern int net_transmit_via ( struct pk_buff *pkb, struct net_device *netdev );
extern int net_transmit ( struct pk_buff *pkb );
extern int net_poll ( void );
extern struct pk_buff * net_rx_dequeue ( void );
#endif /* _GPXE_NETDEVICE_H */
